The present disclosure relates generally to imaging systems and more particularly to imaging systems using synthetic aperture or tomographic imaging techniques.
Synthetic aperture radar (SAR) images a target region reflectivity function in the multi-dimensional spatial domain of range and cross range [I]. SAR synthesizes a large aperture radar. The cross range resolution of the SAR is Rλ/D, where D is the synthetic aperture, R is the target range, and λ is the wavelength of the measured waveform.
When imaging a target, the conventional SAR theory does not include the effects of multiple scattering from the surrounding objects in a high clutter area. In addition to the true target image, multiple-bounce echoes caused by surrounding scatterers produce spurious and random patterns in the formed SAR image. We refer to these as ghost images. A common practice to distinguish the true target from its ghost images is leading edge detection, i.e., if the ghost image is caused by trailing echoes, we may identify the peak that has the shortest range as the target. However, unless we know a priori where the scatterers are, or what their physical characteristics are, it is difficult to distinguish the true target from the ghost images.
Thus, a need exists for a SAR imaging system having improved performance